cisco QOS配置案例

cisco QOS配置案例

 

典型QoS配置案例 

一般的QoS配置不外乎四个步骤： 

1，设置ACL匹配应用流量； 

2，设置class-map匹配相应ACL或者相应端口等等，不过一般式匹配ACL； 

3，设置policy-map匹配class-map，然后定一规则动作； 

4，将policy-map绑定到相应的接口上。下面使用一个比较典型的案例来说明QoS的配置步骤：需求：路径带宽为622Mbps，四种应用流量，需要保证如下几点： 

流量1，某一具体应用流量，永远优先传输，最小带宽保证为365Mbps； 

流量2，某一具体应用流量，次优先传输，最小带宽保证为200Mbps； 

流量3，此为业务流量，保证在1和2后的其余带宽下传输即可； 

流量4，某一具体应用流量，保证在123流量外的带宽下传输即可。具体配置如下： 

第一步，定义ACL匹配应用流量： 

ip access-list extended tra1_acl 

permit tcp 1.1.1.0 0.0.0.255 1.1.2.0 0.0.0.255 eq 8818 

ip access-list extended tra2_acl 

permit tcp 1.1.3.0 0.0.0.255 1.1.4.0 0.0.0.255 eq 901 

ip access-list extended tra4_acl 

permit ip 1.1.5.0 0.0.0.255 1.1.6.0 0.0.0.255 

第二步，定义class-map匹配相关ACL： 

class-map match-all tra1_cmap 

match access-group name tra1_acl 

class-map match-all tra2_cmap 

match access-group name tra2_acl 

class-map match-all tra4_cmap 

match access-group name tra4_acl 

第三步，定义policy-map： 

policy-map tra_pmap 

class tra1_cmap 

    set precedence 5 

plicy cir 365000000 bc 8500000 be 13500000 conform-action transmit exceed-action set-prec-transmit 3 violate-action set-prec-transmit 2 

    bandwitch 365000 

class tra2_cmap 

    set precedence 4 

policy cir 200000000 bc 10000000 be 13000000 conform-action transmit exceed-action set-prec-transmit 3 violate-action set-prec-transmit 2 bandwidth 200000 

class tra4_cmap 

    set precedence 1 

class class-default 

    set precedence 2 

第四步，绑定policy-map于相应的接口： 

int pos1/0/0 

service-policy output tra_pmap 

至此，配置完毕。通过命令查看policy-map的匹配情况： 

switch-a#sh policy-map interface pos1/0/0 

POS1/0/0 Service-policy output: tra_map    Class-map: tra1_cmap (match-all) 

      66639423781 packets, 74849682635166 bytes 

      30 second offered rate 260369000 bps, drop rate 0 bps //匹配此class-map的流量速率 

      Match: access-group name tra1_acl 

      Queueing 

      queue limit 91250 (packets) 

      (queue depth/total drops/no-buffer drops) 0/0/0 

      (pkts queued/bytes queued) 66639405294/74849695040832 

      QoS Set 

        ip precedence 5 

          Packets marked 66639423781 

      police: 

          cir 365000000 bps, bc 8500000 bytes, be 13500000 bytes //注意cir、bc和be的单位 

        conformed 66191701966 packets, 74341131469597 bytes; action: transmit 

        exceeded 218369922 packets, 232627302399 bytes; action: set-prec-transmit 4 

        violated 229208950 packets, 275718927918 bytes; action: set-prec-transmit 3 

        conformed 256761000 bps, exceed 1656000 bps, violate 1939000 bps //每个action的流量速率，注意这三个值总和应该大致等于上面的总速率； 

      bandwidth 365000 kbps     Class-map: tra2_cmap (match-all) 

      11315788699 packets, 7283900643868 bytes 

      30 second offered rate 10753000 bps, drop rate 0 bps 

      Match: access-group tra2_acl 

      Queueing 

      queue limit 50000 (packets) 

      (queue depth/total drops/no-buffer drops) 1/0/0 

      (pkts queued/bytes queued) 11315783713/7283897663316 

      QoS Set 

        ip precedence 4 

          Packets marked 11315788699 

      police: 

cir 200000000 bps, bc 10000000 bytes, be 13000000 bytes 

        conformed 11315784826 packets, 7283898283723 bytes; action: transmit 

        exceeded 0 packets, 0 bytes; action: set-prec-transmit 3 

        violated 0 packets, 0 bytes; action: set-prec-transmit 2 

        conformed 10753000 bps, exceed 0 bps, violate 0 bps 

      bandwidth 200000 kbps     Class-map: tra4_cmap (match-all) 

      1751296887 packets, 2633425803184 bytes 

      30 second offered rate 149000 bps, drop rate 0 bps 

      Match: access-group name tra4_acl 

      QoS Set 

        ip precedence 1 

          Packets marked 1751296887     Class-map: class-default (match-any) 

      22956539608 packets, 17721898306471 bytes 

      30 second offered rate 196094000 bps, drop rate 528000 bps 

      Match: any 

      queue limit 14250 (packets) 

      (queue depth/total drops/no-buffer drops) 0/9004701/0 

      (pkts queued/bytes queued) 24700897941/20350618920708 

      QoS Set 

        ip precedence 2 

          Packets marked 22958504481 

switch-a#必要命令解释： 

plicy cir 365000000 bc 8500000 be 13500000 conform-action transmit exceed-action set-prec-transmit 3 violate-action set-prec-transmit 2 

cir为承诺的带宽速率，即需要保证的带宽速率，单位为bps； 

bc为普通突发，单位为bytes； 

be为最高突发，单位为bytes； 

set-prec-transmit，表示设置IP优先级并转发数据包； 

上面整体命令解释为：承诺带宽365Mbps，普通突发为8.5Mbytes，最高突发为13.5Mbytes。当速率小于450Mbps（365+85）是转发数据包，当超过450Mbps小于500Mbps（365+135）是重写IP优先级为3并转发数据包，当超过500Mbps是重写IP优先级为2并转发数据包。